Switch to 21*21

19x19 did offer a good balance between territory and influence.
But it seems to be broken:

-Alphago invades at San San in the early fuseki.
-Territory has more prestige among professionals as influence (like if they were playing go on a 9x9)

So should we start to play on a 21*21 by now?


Even AG and latest pro games are way less territorial than most of 100+ year old games I have seen. If it wasn’t argument for upsize then, I am not sure why it should be today.


LOL, when playing against AI, perhaps :wink:


Good point. but in that case it’s more like center was too big as too small… Until Goseigen

The board has already historically been upgraded from 17 to 19 so nothing impossible.

Alphago invades at sansan, however it still plays the first moves on the hoshi. That looks very balanced to me.

Also, you’re assuming that increasing the board size gives more weight to the center (4th line and above). I believe that it is the opposite. The larger the center, the more uncertain it becomes, and the more tempting it is to secure the corner early.


I would give kind of same answer as before. Old time= difficult/ Goseigen=center cool/AG=center a bit small
But the 4-4 argument is interesting.

I’m aware of that … and I believe that stepping up to 21x21 will sure happen some day … but I also believe that this will happen naturally when enough humans realise that 19x19 has nothing more to offer (i.e. when we begin seeing more 21x21 games), not when machines beat us on 19x19.

I’m sure you know that it’s possible to play larger boards on OGS, have you tried so already? Sometimes you can see such a board in the games overview, sometimes even larger ones. You can always create such a challenge …

What I’d like to know now is how long it took 19x19 to become standard size, quite sure it didn’t happen in a day, or week, or even year. Perhaps rather a not-so-steep slope for a decade or two, and then climbing up more rapidly, hyperbolic?

OTOH even pros still play 9x9some times (there exist 9x9 pro game collections elsewhere on the ’net) … so “has nothing more to offer” probably is not expressed accurately.


That’s let me think, would be interesting to see how AG would manage a 21x21.
(I didn’t heard on that)
Would she have some kind of fun new opening beyond our intelligence?

@trohde it happens sometimes they play gomoku too! (5 in a row)

this is a subject i have been mulling over ever since the first of the alpha go games. but since there my thoughts on this have developed beyond the reasoning, “Alphago can beat humans on 19x19 so why not go bigger?”

the reason i have developed my thinking beyond that is because at some point AI will just catch up again, and what would we do then? go bigger again? and then the same thing happens, and then we go bIgger once more and so on… my question is where does it end?

My thought on this is that 19x19 go is something that has been around for many hundreds of years, possibly thousands, and we are still learning how to play that properly. It isn’t a solved game. There are no right and wrong answers when you get passed a certain point in go. Its a nebulous concept of a game to begin with. I do however think that now, or soon, would be the time to make the push to a larger board, possibly even something as large as a 25x25. My reasoning on this is simple. the larger board will be harder, and will teach many people smarter than i am, but myself also, what is really important on a smaller board, what better ways are there or optimal plays on the smaller boards. It may seem backward because many people learn on a 9x9 board and advance to 13x13 and so on until they play on a 19x19. But when you learn to play on the larger boards, it also improves your game on the smaller board. And that is my thinking. We should try a larger board, to learn how to play better on smaller boards. But beyond that again… Larger boards should be played not just to learn about smaller moves, but to learn more about he game itself, the nebulous relationships that stones have even when they are so far apart.

In my opinion there are more reasons to play on a larger board than there are on a smaller board. However, i do think think the world or the pro leagues of pro players are ready to increase the size of a standard board, not for competitions and the like anyways.

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Maybe you did mean “are not ready…”?
I got same feelings as you tell here

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If you go for bigger boards, the time a game takes grows as well. How much time do you want to spend on a single game? At some point it gets impossible to do live games.


Especially in today’s world, but the trend could change too.

There was a time and still is that pro games were played over weeks. I don’t think the time of a game should be a factor.

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The conclusion is right if you assume that smaller boards emphasize territory and larger boards emphasize influence. I think we have lots of reasons to believe this might not be true, though. On 9x9, for example, center moves are the most popular first moves by far. In 13x13, Remi Coulom’s “zero” bot, which could be the strongest AI to appear on CGOS 13x13, opens with dual 4-4s. (See Weights_54.)

We don’t have superhuman data for larger boards, but I strongly suspect it would resemble 19x19 play, just on a larger board. This is because the principles don’t change: being near two sides still encircles more points with less effort and makes living easier. Even on a 25x25 board, I think I would prioritize early corner enclosures and 3x3 invasions.


I expect the size to get bigger before the time go gets a bit more popular, till now only very few people enjoy the game. Has always been like this, this game is just too hard, so Increased time won’t hurt too much our societies

i don’t disagree with you that corners are always going to be a vital point for life and points in the game of go. but beyond corners on a larger board is where we will see the biggest difference. Especially in things like ladders. the whole centre game and the sorts of moves played there may very well be radically different than we know what is standard. And with fights being so much larger there will be more and at the same time, less at steak. and sides become nearly impossible to completely dominate.

@violaine i don’t think its because the game is unpopular that is causing the game not to expand on to larger boards. hell if that were true then so would the reverse be true as well. With pros playing on smaller boards just because of time, and bite sized games for the average consumer.

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I would really love to see some AG Vs AG with no human knowledge training on a bigger board. Just to see


it would be interesting. though i suspect a basic understanding of go would at least be nice. and how many times would it take for it to be a 9 dan on a larger board?

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Give me one TPU and I’ll make it happen :wink: